Multiple fuel burner



Jan. 2,,1945. R. c. VROOM ET AL 2,366,453

' MULTIPLE FUEL BURNER Filed May 29, 1942 2 Shaets-Sheet l INTO/FIVE) Jan. 2, 1945; R. c. VROOM ET AL 2,365,463

MULTIPLE FUEL BURNER Filed May 29, 1942 2 Sheets-Sheet 2 IN VEN TORS Jfolveri (Z Woom y Baa/1d i? [Ira/1am Patented Jan. 2, 1945 UNITED STATES PATENT OFFICE MULTIPLE FUEL BURNER Robert C. Vroom, Montclair, N. J., and David P. Graham, Flushing, N. Y., assignors to Peabody Engineering Corporation, New York, N. Y., a corporation of New York Application May 29, 1942, Serial No. 444,956

communicates with an air register 2| and the 5 Claims.

This invention relates to burners for liquid, gaseous and pulverized fuels, and has for its object to .provide a new and improved burner of this type which is adapted to burn eificiently a variety of such fuels, either simultaneously or separately.

Another object of the a burner of the above -type which is adapted toburn a variety of fuels differing in heat content,

cleanliness, pressure, etc.

Another object is to provide a combination burner for a plurality'of different fuels, employcut more particularly in the claims appended w hereto, the invention itself may be better understood by referring to the following description, taken in connection with the accompanying drawings forming a part thereof, in which a specific embodiment of the invention has been set forth for purposes of illustration.

In the drawings,

Fig. 1 is an end view of a burner embodying the present invention; and

Fig. 2 is a longitudinal sectional view thereof.

' throat II.

In the following description and in the claims certain specific terms have been used for convenience in referring to various details of the invention. These terms, however, are to be given as broad an interpretation as the state of the ring l6 which registers with the burner throat The casing I is divided axially into an air chamber l1 and a fuel chamber l8 by means of a division plate l9 extending between the peripheralwall l and'a central cylindrical burner tube 20, the forward (fireroom) end of which rear (furnace) end of which is spaced fro-m the throat ring 16 to provide an annular fuel passage 22 therebetween. The division plate I!) is invention is to provide shown as a helical'plate, 360 in extent from its forward end |9a to its furnace end I91), and these ends thereof, which are displaced axially, are joined by an axially extending plate 23. The air chamber I1 is provided with a rectangular air inlet passage 24 and the fuel chamber I8 is provided with a fuel inlet passage 25, shown as disposed peripherally, which extends the full axial and radial width of the fuel chamber 18 betweenthe forward end |9a of the division plate l9 and the rear wall I4. By reason of the spiral =3; peripheral wall l5 the cross sectional area of the fuel chamber for gas flow progressively decreases from the zone of fuel admission so as to equalize the gas flow through the annular fuel exit pas sage 22 around the entire burner throat. By making the division plate |9 helical as shown the fuel chamber l8 tapers in section both radially and axially and a square or nearly square crosssection is obtained, a shape which gives minimum'pressure loss. In certain instances the division plate may be made flat instead of helical if the gas flow is found to have the required characteristics. l

An annular wall 26 is attached to the throat ring l6 and to the rear wall M to form a second annular gas chamber 21 having a gas inlet passage 28 communicating therewith. An annular row of gas outlet ports 29 is provided in the throat ring Hi to discharge gas from the annular gas chamber 21 for combustion in the burner The second annular gas chamber 21 may, of course, be made tubular or of other cross-sections and the gas discharge openingmay be annular or of other form. Ports 29 have been shown merely as an illustration.

The burner is stiffened by radial struts 30 and 30a which extend respectively from the burner tube 20 and-the wall 26 to the peripheral wall l5 in radial alignment with longitudinal stilfeners 3|. The entire burner is supported by a frame 32. The portions of the casing forming the air chamber I! may be provided with an insulating lining Illa. The walls of the gas chamber I8 may be similarly insulated if hot gases are to be supplied thereto. The air register 2| may be of any convenient type such as that disclosed in, the Peabody Patent 1,628,424, dated May 10, 1927, andin the Leask et a]. Patent 1,858,674, dated May 1'7, 1932, which includes a housing mounted on a front plate 35 and having a plurality of peripheral air doors 36 adapted to receive air from the air chamber [1 for delivery through a suitable air discharge opening 31 into the fireroom end of burner tube 20. The register air doors 36 are adjusted by means of a suitable handle 38 on the. front plate 35 of the register, and are adapted to control the rotation of the air supplied through the register to the burner tube 20. The insulated register front plate 3.5 may be mounted on the front wall I3 of the burner by bolts 38. The particular form: of air register, however, forms no part of the present invention and is accordingly not set forth indetail.

For the purpose of burning liquid fuel, the burner is provided with an atomizer barrel 40 which extends axially of the burnertube 2 and is provided at its inner end with an atomizer. tip 4| and a diffuser 42 which are disposed adjacent the burner throat IL. The: barrel 40 extends outwardly through the air register 21' and carries a coupling member 43 which; is connected to: the usual fuel supply pipes. 44., The barrel 4?!) and tip 4| maybelretracted whenxnot-i'n use;

The atomizer barrel: may be: of. the type disclosed. more in. detail. in Peabody Patent No: 1,628,424, above mentioned, and: may comprise; for: example;. means. for supplying: liquid fuel under pressure to theiatomizer'tipaand for: dis:-

The; barrel. 40.: also: be designed to: supply gaseous or pulverized fuel and may; be: used: as an i-gniteroras. an. auxiiiary 'fuelfsupplyz. If used only foirinitialaignition theebarrelimay be retract.- ed; after ignition. has: taken: place. The diffuser may alsobe retracted to: a; point nearror. at the furnace end of the: burner tuberlll: to control the directionof air'a-nd fueliflow to the: burner throat.

LowB. t4 u; gaseous; fuels, such as: blast-fur.- nace gas orproducer gas,.often contain moisture and suspended solid matter; When such gases are used as fuel in the chamber l=8.= adeposit or mud? may form upon: the. outer periphery of burner tube 2i), although the shape of the: chamberprovitding uniform" gas flow: and the absence of' pockets has been found; to: keep: such deposits at a: minimum: However; in: order to remove any such deposit which: may form, a steam ring 50- isgpositioned about the burner tube; 2! in chamber l8 adjacent the division-plate l9. This ringis shownas hayingamultiplieity of holes-5.1 for thedischarge. of 'steamabout the tube. 20- in a direction to blow off any deposit. which may be formed thereon. Thesteam ring 50 is supplied at diametrically opposite. points; X and; Y by a, steam. pipe 51 controlled-. bya: valve 53; Steam. blow: means- 'may also bew'providedfor cleaning other. surtfaces oi the fuellchamber t8; Suitable cleanout; and: inspection. doors, 54 are also provided in the, peripheral; wall: l5. Of course other fluid under. pressure. may be used instead of steam for blow off purposes de sired.

A. fuel in suspensiom such as. pulverized coal,

may be suppliedfth theinterior of. burner tube 20 through a. conduit 55. whiohqis; connected to said. tube; substantially tangentially so. that the pillvrified; fuel suspendedqin: carrier air will. engten the. tube. llltangentially and willrotate. and advance about the inner peripheral wall thereof end thereof at the burner throat.

to the burner throat, as shown more in detail in the Leask et al., patent above mentioned. The tube 20 may be provided with helical vanes 56 to direct the flow of fuel around the discharge The conduit 55 passes through the peripheral wall 15 and the air chamber H in the dead air space between the air register 21 and the division plate l9b and therefore does not impede the flow of air through the air chamber IT to the register 2|.

In order to prevent gas leakage from the burner throat or furnace into the fire room, the throat is sealed by ametal cylinder 60 which also serves to supportand retain the throat tile BI and 62 and fits within the throat opening in the wall A furnace plate 64 is secured over the front of the-wall l2 and carries cylinders 65 and 66 which extend into the rows of bricks in the wall I'Z around the throat opening.

Plate 64 projects radially inward at 61 to' a slightly smaller. diameter than the cylinder 66, almost into engagement with the tile support andsealingring 65. An annular flange 68, carried :by the: cylinder 60, is clamped against the furnace plate 64 by bolts 69 which extend through brackets eta attached. to stifieners 3|. Packing. 10 may be-provided to'form a tight seal between the-flange 68- and the plate 64.. Packing H may be insertedbetween. the cylinder 66 and. the; sealing. ring. 66' and may be. packed against the. extension. 621 of: plate 6.4, The re.- maining space between the; outside of. the. ring Stand the wall. bricks may: be sealed. by crushed firebri'ck or high. temperature. cement, 1.1;" which may be packed in after the burner is in place. Any gas which. may leak. radially through. the throat tile=is..stopped by the ring; 60.. Gas leakage passag-es- 12' are. provided-inthe throat tile 61 at thefurnace endof. the ring.v 60 in order to permit: leakage gas to pass freely into the furnace and to thus prevent the building. up of pressureon theoutside of thering 60-.

Aplurality of: tubes '55, extending from. the gas chamber it: through the wall l;2.intovthe furnace, may be spaced around the burner opening. These tubessupply fuel. gas from the chamber. I8 directly into thef-urnace-and may be used for. ignition or stabilization purposes. An annular space 1.3. is provided; betweenthe wall bricks and the plate 64 on the inside. of the-cylinder 65... Air under'a pressurehigher than the gas pressureis supplied thereto by a pipe 14.. The air pressure in the space 13 assists further in causing any gasleakage to take place intothe furnace; Thetilefil. are made 0t smaller inside. diameter than the tile, 62 so; as to. avoid a-forwardly facing shoulder which might be formedv at the joint between. these tile if. they were made of the same diameter and werenot exactly centered and. would tend to impede gas flow.

A guide. vane. ac. mayv be mounted. in. thefiiel chamber IBYbetWeen. the furnace. end lBb: of. the division. plate l9 and the. throatring, l Hand. adjacenttlo. theeaxialplatefir Thisb'afiie 89 is shown as mounted on. arod 8L which extends through the. front, wall 13. and is provided with. a handle 82. The bafile extendsin anupw'ardly inclined direction to regulatethe flow offuel' around the Operation The above described burner is capable of burning a plurality of different fuels simultaneously and of operating efficiently when one or more of the fuels is shut off. For example, in certain plants coke oven gas may be available to supplement the blast furnace gas. The blast furnace gas being available at low pressure requires an admission chamber of substantial size. The chamber I8 is designed for this purpose and has a tapering flow area suited to obtain an even gas distribution around the burner throat. Other gas which may be at a higher pressure is supplied to the smaller annular chamber 21.

Pulverized fuel suspended incarrier air is sup plied to the burner tube 20 and advances helically therein to the burner throat. Liquid fuel may be supplied through the atomizer barrel 40 and atomized in the burner throat from the tip 4| or gas or pulverized co-al may be supplied axially of the burner according to the type of fuel available.

The present invention permits the burner to utilize gaseous fuel alone or in combination with liquid and pulverized fuels as required. The various fuels available at any particular plant may be used simultaneously and may be supplemented by other fuel as required. When operating with any desired fuel, or combination of fuels, the air doors 36 of register 2| are adjusted, by proper manipulation of the operating handle 38, to ob tain the desired direction and speed of airflow to the burner throat II. The combustion air, regulated by the pressure in the air chamber I1. flows through the burner tube 20 as. a rotating mass and is mixed with the fuels under conditions adapted to produce an elficient mixture of air and fuels for combustion.

Although a specific embodiment of the invention has been shown for purposes of illustration, it is to be understood that various changes and modifications may be made therein as will be readily apparent to a person skilled in the art and certain parts, such as tubes 15, vane 80 and blades 90 may be omitted if desired.

What is claimed is:

1. A burner comprising a cylindrical burner tube open to a burner throat, an air register associated with the forward end of said tube remote from the burner throat to supply secondary air thereto, a spiral casing disposed about said burner tube and said air register and forming therewith an annular space of progressively decreasing radial width, a helical division plate extending between said casing and said tube and dividing said annular space into an air chamber open at its forward end to said air register and a fuel chamber of progressively decreasing radial and axial width having an annular opening around the peripheryof the burner tube to the burner throat, a fuel supply duct communicating tangentially with said fuel chamber at its portion of greatest axial width, said fuel duct discharging into said chamber tangentially in the direction of decreasing cross-sectional area to cause fuel to be dischargedaxially through said annular opening to tube open to a burner throat, an air register associated with the forward end of said tube remote from the burner throat to supply secondary air thereto, a spiral casing disposed about said burner tube and said air register and forming therewith an annular space of progressively decreasing radial Width, a helical division plate extending between said casing and said tube and dividing said annular space into an air cham ber open'at its forward end to said air register and a fuel chamber of progressively decreasing radialand axial width having an annular opening around the periphery of the burner tube to the burner throat, a fuel supply duct communicatingtangentially with said fuel chamber at its portion of greatest axial width, said fuel duct discharging into said chamber tangentially in the direction of decreasing cross-sectional area to cause fuel to be discharged axially through said annular opening to the burner throat, an air supply duct supplying air to said air chamber for passage through said air register into said burner tube for mixing with the fuel at said throat, and a second fuel supply duct-extending throughsaid casing and through said air chamber and discharging tangentially into said burner tube at about the location of greatest axial tube length on the air chamber side of said division plate to supply a second fuel to the inside of said tube.

3. A burner comprising-a cylindrical burner tube open to a burner throat, an air register associated with the forward end of said tube remote from the burner throat to supply secondaryair thereto, a spiral casing disposed about said burner tube and said air register and forming therewith an annular space of progressively decreasing radial width, a helical division plate extending between said casing and said tube and dividing said annular space into an air chamber open at its forward end to said air register and a fuel chamber ofprogressively decreasing radial and axial width having an annular opening around the periphery of the burner tube to the burner throat, a fuel supply duct communicating tangentially with said fuel chamber at its portion of greatest axial width, said fuel duct discharging into said chamber tangentially in the direction of decreasing cross-sectional area to cause fuel to be discharged axially through said annular opening to the burner throat, an air supply duct supplying air to said air chamber for passage through said air register into said burner tube for mixing with the fuel at said throat, a second fuel supply duct extending through said casing andthrough said air chamber and discharging tangentially into said burner tube at about the location of greatest axial tube length on the air chamber side of said division plate to supply a second fuel to the inside of said tube, and a fuel ring around and spaced from the end of said burner tube to form said annular opening from said first fuel chamber, said fuel ring having orifices to supply a third fuel for mixing with the secondary air from said burner. tube at the burner throat.

4. A burner comprising a cylindrical burner tube open to a burner throat, an air register associated with the forward end of said tube remote from the burner throat to supply secondary air thereto, a spiral casing disposed about said burner tube and said air register and formingvtherewith an annular space of progressively decreasing radial width, a helical division plate extending between said casing and said tube and dividing said annular space; into: air: chamber open: at. its forward end: to: said; air register and; afuel chamber otprognessively decreasing radial and" axial widthhaving an: annular opening around the periphery of theburnertubeto. the burner throat;

a-f-uel supplyduct communicating tangentially with: said fuel chamber at; its, portion, of greatest axial width; said fuel duct discharging. into said chamber tangentially in the direction of decreasing cross-sectionalarea to: cause fuel to bedischarged axially'through said; annular opening to the'burner throat,ean; air supply duct: supplying air to said air chamber for passagethroughsaid airregister into said burner tube for mixing with the fuel .atsaid throat, peripherally spaced longitudinal stiffeners reinforcing said casing; and radial stiffeners attached to said longitudinalstitreners and extending between said: burner tube and said casing.

5. A burner comprising; acylindrical burner tubeopento aburn'er throat, an'a'ir registerassocia'tedawith the forward end of said tube-remote from the burner. throat to supply secondary air thereto a spiral casing disposed about said; burner tube and said air register. and: forming; therewith an annular space 0151 progressively decreasing raascen s dial width, a'helical division plate extending beet-ween: said casing and said tube and dividing said annular space into an air chamber open at its forward end to said air. register and a fuel chamber of progressively decreasing radial and axial. width having an annular opening around the periphery of the burner tube to the burner throat; a fuel supply duct communicating tangentially withsaid fuel chamber at its portion of greatest axial width, said fuel duct discharging into said chamber tangentially in the direction of decreasing cross sectional area to cause fuel to be discharged axially through said annular opening to the burner throat, and an air supply duct supplying air to said air chamber for passage through said air register into said burner tube for mixing with the fuel at said throat, a fluid manifold around said burner tube on the fuel chamber side of said division plate having openings disposed to blow ofi accumulations' from the surface of said tubeand connections to supply fluid under pressure to said manifold.

ROBERT C. VROOM.

DAVID P.- GRAHAM.

CERTIFICATE OF CORRECTION Patent No. 2,566,h65. January 2, 191

ROBERT c. vsoom, ET AL.

It is hereti; certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column; line M for "B. t. u." re ad --B.' T. U.-; and second column, lines 25 and 50 respectively for "ring 66 read "ring 60- and that the said Letters Patent should be read with this correction therein that the same may conform to the record of vthe case in the Patent Office.

Signed and sealed this 10th day of April, A. D. 191.15.

Leslie Frazer (Seal) 7 Acting Commissioner of Patents. 

